Many Android devices have a several storage options for example in addition to the small internal built-in storage users can also insert SD cards with extra capacity. This is in contrast to Apple mobile devices like iPhone and iPad where users are stuck with the internal storage to save different games, apps and video data. There is no option for expandability in Apple devices (at least so far). If you have Samsung Galaxy S4 or some other Android device where you are running short on internal storage capacity due to the installation of large apps, games data or videos for example then you can use the freely available app called FolderMount to move the desired space consuming folders to the external SD card storage. Android version from 2.3 to 4.2.2 is supported by the FolderMount currently.

unnamed3 | How to Move Internal Data to SD Card  to Free Up Space on Samsung Galaxy S4 and Other Android Devices

Note that a root is required for this application to work. If you have the root on device then it should work without problem and move the contents of the desired folder to the external card and linking it the same folder on your internal device memory.

Here is how to move data from internal storage to external SD card according to the developer of the app:

* Add a folder pair. Source is the internal sdcard and destination is your extSdCard
* After adding, FM will offer to move the files for you. Click yes.
* Wait until the move operation is done then click on the PIN. If PIN turns green, you’re all set.
* The files will exist in both the source and destination after mounting. This is expected and is normal. The files you see in your internal sdcard actually reside in your external sdcard now and if you "unpin" the pair, you’ll see that your internal sdcard is empty again.

FolderMount  can download from the Google Play store here.